1. Field of the Invention
The invention relates to tranducers for mechanical measured variables, and more particularly pressure transducers.
2. Description of the Prior Art
Transducers, especially for measurements in internal combustion engines, normally are either provided with a cooling device or they are constructed in a manner to resist high temperature loads, so that a cooling device is not necessary. In cooling systems heat transport is usually transformed by means of the forced flow of a fluid or air.
It is a disadvantage of the known, cooled transducers to require external equipment for the cooling device. Transducers without a cooling system are exposed to high thermal stress or one said thereof. Due to the limited thermal conductivity of the usable materials a part of the transducer is disproportinately heated and therefore problems appear because of the selection of suitable materials and sensors (e.g. piezoelectric crystals, strain gauges, piezo resonators). The resulting temperature gradient is variable with time and inhomogeneously distributed over the sensor element. These undefined temperature conditions make it difficult to compensate the thermal sources of error, which occur in consequence of the variable expansion and the temperature dependence of the physical properties of the sensor.